Attachment for sewing machine



March 22, 1955 B. F. RENN ATTACHMENT FOR SEWING MACHINE 2 Sheets-Sheet 1Filed July 24, 1953 INVENTOR. fieizizz'efifiierzfz,

ATTEI R N EYS March 22, 1955 R ATTACHMENT FOR SEWING MACHINE 2Sheets-Sheet 2 Filed July 24, 1953 I IN 'ENTO R. fiezzzzzemeizfz,

ATTD RN EYS United States Patent ATTACHMENT FOR SEWING MACHINE Bennie F.Renn, Jefferson City, Mo.

Application July 24, 1953, Serial No. 370,123

4 Claims. (Cl. 112-67) This invention relates to a sewing machine, andmore particularly to a mechanism for automatically and s1- multaneouslyraising and lowering the presser foot and actuating the starting leverof a sewing machine.

The object of the invention is to provide a sewing machine wherein asingle attachment is provided for raising the presser foot and trippingor starting the sewing machine.

Another object of the invention is to provide a labor saving attachmentwherein a single foot treadle can be used to operate both the work clampand to start the stitching cycle.

Another object of the invention is to provide a servo control for sewingmachines, bar tackers, button sewers, fiy tackers, tick-tackers and thelike, wherein a single pedal can be used for raising the presser footand starting the sewing machine.

A further object of the invention is to provide a sew ing machineattachment which is extremely simple and inexpensive to manufacture.

Other objects and advantages will be apparent during the course of thefollowing description.

In the accompanying drawings, forming a part of this application, and inwhich like numerals are used to designate like parts throughout thesame:

Figure 1 is an end elevational view of the sewing machine attachment,and showing the position of the parts when the sewing machine is notrunning.

Figure 2 is a fragmentary top plan view of the attachment.

Figure 3 is a view similar to Figure 1, but showing the position of theparts when the sewing machine is working or running.

Figure 4 is a view showing the locking dog in normal position when thesewing machine is not running.

Figure 5 is a fragmentary elevational view showing the thread cuttingarm.

Figure 6 is a horizontal sectional view taken through the shaft andshowing the clamp with the case hardened p ate.

Figure 7 is a front elevational view of the clamp of Figure 6.

Figure 8 is an elevational view showing the equalizing arm in startingposition.

Figure 9 is a view similar to Figure 8, but showing the initial positionof the parts in the event that the chain leading to the presser footstops moving.

Figure 10 is a view similar to Figure 8 but showing the position of theparts if the shaft stops moving first.

Figure 11 is a view showing the dog in latched or locking position withrespect to the clamp.

Figure 12 is a view similar to Figure 11 but showing the parts inreleased position.

Referring in detail to the drawings, the numeral 10 designates the baseor bed of the sewing machine which may be any type of sewing machine ofconventional construction. The usual pulley 11 is provided, and theattachment of the present invention includes an L-shaped bracket 12 thatmay be made of any suitable material such as metal. The bracket 12includes a vertically disposed portion 14 and a horizontally disposedportion 15, Figures 1 and 3, and an inclined brace'16 extends betweenthe portions 14 and Hand is secured thereto in any suitable manner, asfor example by welding. A bearing 17 is secured to the vertical portion14 of the bracket 12 for a purpose to be later described.

Slidably mounted in the bearing 17 is a vertically 2,704,525 PatentedMar. 22, 1 955 shiftable shaft 18 which is provided with a head or cap19 on its upper end. A coil spring 20 is circumposed on the shaft 18 andis interposed between the head 18 and the bearing 17 for normally urgingthe shaft 18 into its raised position as shown in Figure 1.

Positioned on the shaft 18 below the bearing 17 is a clamp 21, therebeing a set screw 22 for maintaining the clamp in place on the shaft. Acase hardened plate 23 is secured to the clamp 21 by suitable screws orbolts 24, Figures 6 and 7. The case hardened plate 23 is adapted to beengaged by a hook 25 on the upper end of a pivotally mounted dog 26,Figures 11 and 12. The dog 26 is pivotally connected to a bracket 28 bymeans of a bolt and nut assembly 27 which extends through the bracket 28that is secured to the vertical portion 14, Figure 1. Formed integralwith the lower end of the locking dog 26 or secured thereto is a yoke 29of substantially U-shape, and the yoke 29 has a straight section or flatsection 30 extending therefrom for a purpose to be later described, Theflat portion 30 of the locking dog 26 is adapted to be engaged by athread cutting arm 31 which is pivotally connected to the sewing machineby means of a pin 32, Figure 5. Thus, when the thread cutting arm 31moves over to engage the portion 30 the locking dog 26 will move fromthe position shown in Figure 11 to the position shown in Figure 12 sothat spring 20 can move the parts from the position shown in Figure 3 tothe position shown in Figure 1.

The numeral 33 designates the trip lever for starting the sewing machinein the usual manner, and the numeral 34 indicates a chain which extendsbetween the trip lever 33 and an end of an equalizing arm 35. The lowerend of the vertically sliding shaft 18 is provided with a slot orcut-out 36 and an end of the equalizing arm 35 is pivotally mounted inthe slot 36 by means of a pin 37. A pull down chain 38 is connected tothe equalizing arm 35, and the pull down chain 38 may be manuallyactuated or it may be connected to a conventional foot treadle. Thus, byactuating such a foot treadle the pull down chain 38 can be moved totrip lever 33 to stop the sewing machine and also the presser foot canbe lowered as later described in this application.

Mounted on the base of the sewing machine is a bracket 39 which has abottom portion 40 secured to the sewing machine by a bolt or screw 41. Apair of spaced parallel apertured ears 42 extend upwardly from thebracket, and a lever 43 is pivotally mounted between the ears 42 bymeans of a pin 44. One end of the lever 43 is bifurcated as at 45 forslidably receiving the shaft 18, the bifurcated end 45 being interposedbetween the clamp 21 and the bearing 17. A chain 46 is connected to theother end of the lever 43, and the chain 46 may be connected to theusual presser foot or clamping foot of the sewing machine. When thelever 43 is in the position shown in Figure 1 the clamp or presser footis raised from the work, and when the parts are in the position shown inFigure 3 the pivotal movement of the lever 43 permits the presser footto lower or rest on the work being sewed.

From the foregoing it will be seen that there has been provided anattachment for a sewing machine whereby a single foot treadle connectedto the chain 38 can be used for simultaneously lowering the presser footwhich is operatively connected to the chain 46 and for also actuatingthe trip lever 33 which energizes the sewing machine or starts the cycleof stitching. In use by pressing down on the treadle connected to thechain 38, the equalizing arm 35 will be moved downwardly from theposition shown in Figure 8 or from the position shown in Figure 1 to theposition shown in Figure 3. As the arm 35 moves downwardly it pulls theshaft 18 downwardly and the shaft 18 carries the clamp 21 therewith.When the clamp 21 gets below the hook 25 of the lockmg dog 26, thespring 47 urges the locking dog 26 from the position shown in Figure 12to the position shown in Figure 11 so that the shaft 18 is maintained inits downward position as shown in Figure 3 during the sewing operation.When the parts are in the position shown in Figure 1 the lever 43 ismaintained in a substantially horizontal position, but when the shaft 18moves downwardly, the lever 43 is permitted to pivot in acounterclockwise direction so that the chain 46 permits the presser footto drop onto the work at the same time that the trip lever 33 actuatesthe sewin machine. The spring 47 is circumposed on the bolt and nutassembly 27, as shown in Figure 2 of the drawings, and one end of thespring 47 is arranged in engagement with a suitable aperture or openingin the bolt of the bolt and nut assembly 27. The other end of the coilspring 47 is arranged in engagement with a suitable aperture or openingin the locking dog 26 as shown in Figure 4 so that the coil springexerts a constant pressure on the locking dog 26. After the completionof the sewing operation, the thread cutting arm 31 automatically movesover and engages the flat portion 30 on the yoke 29 to thereby pivot thedog 26 from the position shown in Figure 11 to the position shown inFigure 12 whereby the spring 20 returns the parts to the position shownin Figure 1. Thus, the lever 43 will be pivoted from the position shownin Figure 3 back to the position shown in Figure 1 so that the presserfoot connected to the chain 46 will be automatically raised away fromthe work. Further, with the parts returned to the position shown inFigure 1 the trip lever 33 will de-energize the sewing machine at thesame time.

The present attachment provides a completely automatic mechanism so thatthe work clamp or presser foot and stitching cycle can be started by onetreadle at the same time. The attachment can be used on Singer sewingmachines, bar tackers, button sewers, fly tackers, tick-tackers and thelike. Ordinarily these machines require two foot pedals for raising thefoot and tripping or starting the machine but with the presentattachment both operations are accomplished with the use of only onefoot pedal. After the machine has completed the sewing operation andupon the thread cutting operation of the machine, the thread cutting bar31 moves to release the catch or dog 25. The case hardened portion orplate 23 which is engaged by the hook 26 insures that there will be noexcessive wear on this part.

After the completion of the sewing operation, the thread cutting bar 31is moved to pivot or unlock the dog 26 from the clamp 21. The dog 26when in the position shown in Figures 3 and 11 serves to maintain theparts down as shown in Figure 3 during the sewing cycle. After thecompletion of the sewing cycle, the thread cutting bar 31 moves over andtrips the dog 26 to permit the spring 20 to move the shaft 18 and lever43 back to the position shown in Figure 1. When the sewing machine isnot operating, the equalizing arm 35 is horizontal as in Figure 8. Inthe event that the chain 46 resists downward movement while the shaft 18moves downward as in Figure 9, continued downward pulling on theequalizing arm 35 by means of the chain 38 will then pull the chain 34downward so that the presser foot and trip lever will eventually beactuated. Similarly, as shown in Figure if the chain 34 moves downwardahead of the shaft 18, continued downward pulling on the arm 35 by thechain 38 will result in eventual downward movement of the shaft 18. Thetrip lever 33 may be used for starting the motor that operates thesewing machine. The mechanism of the present invention can be used onvarious types of conventional sewing machines as for example themechanism can be used on the following types of Singer sewing machines.Machines of the bar tacker Class 69-5; tacker Class 114 31; buttonsewerfly tacker Class 69 18669-26.

I claim:

1. In a sewing machine, a base, an L-shaped bracket secured to saidbase, a bearing secured to said bracket intermediate the ends thereof, ashaft slidably mounted in said bearing, a head mounted on the upper endof said shaft, a coil spring circumposed on said shaft and interposedbetween said head and bearing, a body member secured to said base, alever pivotally connected to said body member and provided with abifurcated end for slidably engaging said shaft, a clamp secured to saidshaft and spaced below said lever, a chain connected to an end of saidlever, and adapted to be connected to a presser foot, a pivotallymounted dog provided with a hook on its upper end mounted for movementinto and out of engagement with said clamp, there being a slot in thelower end of said shaft, an equalizing arm extending into said slot andpivotally connected to said shaft, a chain having its lower endconnected to said arm and its upper end adapted to be connected to atrip lever for starting the sewing machine, and a pull chain con nectedto said arm intermediate its ends.

2. The apparatus as described in claim 1, and further (iincluding aspring arranged in engagement with said 3. The apparatus as described inclaim 1, and further including a case hardened plate secured to saidglamp and adapted to be engaged by the hook on said 4. In a sewingmachine, a base, a bracket secured to said base, a bearing secured tosaid bracket intermediate the ends thereof, a shaft slidably mounted insaid hearing, a head mounted on the upper end of said shaft, resilientmeans circumposed on said shaft and interposed between said head andbearing, a body member secured to said base, a lever pivotally connectedto said body member and slidably engaging said shaft, a clamp secured tosaid shaft and spaced below said lever, a chain connected to an end ofsaid lever, and adapted to be connected to a presser foot, a pivotallymounted dog provided with a hook on its upper end mounted for movementinto and out of engagement with said clamp, there being a slot in saidshaft, an equalizing arm extending into said slot and pivotallyconnected to said shaft, a chain having its lower end connected to saidarm and its upper end adapted to be connected to a trip lever forstarting the sewing machine, and a pull chain connected to said armintermediate its ends.

References Cited in the file of this patent UNITED STATES PATENTS806,231 Allen Dec. 5, 1905 1,221,254 Weis Apr. 3, 1917 1,822,854 AllenSept. 8, 1931 2,540,730 Hayes Feb. 6, 1951

